The present invention relates in general to devices for conveying products and it was developed with particular attention to its use within automatic packaging machinery.
More in particular, the invention relates to the techniques that allow to form groups of products, in particular food products such as biscuits or the like, to obtain packages, each containing a predetermined quantity of products. This possible application, whereto reference shall be made hereafter, must not in any case be construed to limit in any way the scope of the invention.
The invention was developed in particular for an installation for the production of packages formed by a certain quantity of products, mutually stacked or set side by side. Usually, the individual products destined to be grouped are carried to the inlet of a packaging station in the form of a continuous array of stacked or side by side products. To obtain the package, therefore, it is necessary to subdivide the continuous array of products advancing along a direction of conveyance with the products in mutual contact into groups of products distanced from each other at regular intervals.
To fix ideas, one can consider biscuits having flattened shape, mutually superposed to form a stack wherefrom blocks or packs (usually called “slugs”) are to be obtained, each to be inserted in a package or part of a package.
In traditional solutions adopted in the prior art to perform this function, an array of products is made to advance along a conveyance path with the products in mutual contact and cyclically to insert in the array, in a predetermined area of the conveyance path, a separator element (for example shaped as the blade of a knife, in order to separate from the array successive groups of products downstream of the separator element.
The insertion of a separator element between two products in mutual contact in a continuous array is a delicate operation, especially in the case of oven-baked products such as biscuits or the like with irregular surfaces and subject to ample dimensional tolerances. The insertion of the separator element could cause the rupture of a product if, for example due to the irregular dimensions of the products, one of the products is positioned on the trajectory of insertion of the separator element.
The insertion of a separator element between two products in mutual contact in a continuous array is an operation that can become even more critical if the products have a convex face and a concave shape and are stacked or set mutually side by side with the concave face of a product in contact with the convex face of the immediately subsequent or preceding product. In such cases, the risk of rupture of a product during the insertion of a separator element is very high.
The object of the present invention is to provide a device and a method for forming groups of products which allow to overcome the aforesaid drawback.
According to the present invention, said object is achieved by a device and by a method having the characteristics set out in the claims.